Buses running up and down the streets of San Francisco are plastered with ads for Covered California, the state’s official health insurance exchange. But a passenger who goes home and visits coveredcalifornia.com on Thursday would be greeted with a blank white page—not because of any website glitches, but because it is one of ten imitation sites that has been shut down by the California Attorney General’s office.

“These websites fraudulently imitated Covered California in order to lure consumers away from plans that provide the benefits of the Affordable Care Act,” state Attorney General Kamala Harris said in a statement. “My office will continue to investigate and shut down these kinds of sites.” Officials from Washington to New Hampshire have been dealing with websites that closely resemble government portals. The Kentucky Attorney General has sent cease and desist letters to similar mimicker websites, and Pennsylvania officials shut down a private “exchange” site brandishing the state’s seal this summer.

In August, TIME reported concerns from consumer advocates who feared that scammers would capitalize on the confusion caused by the Oct. 1 launch of the law’s health insurance exchanges. “There are people licking their chops and saying, ‘A sucker is born every minute,’” said Elizabeth Abbott, director of administrative advocacy for the consumer group Health Access California. Similar problems plagued Massachusetts after the state passed comprehensive health care reform in 2006.

Insurance purchased through these imitator sites, many of which are run by private health insurance brokers, may not comply with the coverage standards required by the Affordable Care Act, which prevents insurers from rejecting people with preexisting conditions and eliminates the financial cap on covered services.

But the concerns go beyond consumers buying insurance that lacks the full protections afforded by Obamacare. Some sites might sell insurance that only pays for a tiny slice of a patient’s costs or may sell “discount medical plans” that just look like insurance. Others may be run by identity thieves who aren’t selling anything, only using the site as a means of getting people’s personal and financial information.